Technical Aspects of a Rocket-Noise Monitoring System
William Bringier · The Journal of the Acoustical Society of America · 1966
This paper describes the design philosophy of a system to monitor rocket noise in communities located miles from the site of the test vehicle. Pole-mounted remote units are designed for continuous operation with high stability and reliability over varying ambient conditions. Commercial leased telephone lines are used to transmit a data band of 0.1–350 cps. Equipment protection against transient voltages on telephone lines is a primary requirement. The use of a temperature-controlled microphone and a preamplifier with an input impedance of over 25 000 MΩ permits utilization of a commercially available piezoelectric microphone cartridge in an outdoor environment with low-frequency response to 0.1 cps. The Base Station accepts up to eight inputs and provides signal conditioning for direct record of all channels simultaneously, permitting analysis at a later time. Continuous monitoring of any input and real-time demodulation with meter readout directly in sound-pressure level are featured in this versatile system.